Remove workaround for missing package on nuget.org

Update the aspnetcore-build images to contain the 2.0.2 .NET Core SDK (…

…#312)

Update the 2.0 images and tags to ASP.NET Core 2.0.0

Merges staging into master

Merge pull request #255 from aspnet/staging

Adding 2.0.0-preview2 Dockerfiles

Add 2.0.0-preview1 images

⚠️ Move 'latest' and 'lts' tags to MSBuild SDK instead of projectjson

Update build images to RC4
Update README.md
React to changes in dotnet new
Fix test script and include more test logging

ASP.NET Core 1.0.1

1. Packages cache (1.0.1 10055 build)
2. Preload node, npm, gulp and bower